Make the LayoutRect->FloatRect constructor explicit.

Source/core/html/HTMLCanvasElement.cpp

 /*
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 280 matching lines @@
 
     // Propagate the m_dirtyRect accumulated so far to the compositor
     // before restarting with a blank dirty rect.
     FloatRect srcRect(0, 0, size().width(), size().height());
     m_dirtyRect.intersect(srcRect);
     LayoutBox* ro = layoutBox();
     // Canvas content updates do not need to be propagated as
     // paint invalidations if the canvas is accelerated, since
     // the canvas contents are sent separately through a texture layer.
     if (ro && (!m_context || !m_context->isAccelerated())) {
-        LayoutRect mappedDirtyRect(enclosingIntRect(mapRect(m_dirtyRect, srcRect, ro->contentBoxRect())));
+        LayoutRect mappedDirtyRect(enclosingIntRect(mapRect(m_dirtyRect, srcRect, FloatRect(ro->contentBoxRect()))));
         // For querying DeprecatedPaintLayer::compositingState()
         // FIXME: is this invalidation using the correct compositing state?
         DisableCompositingQueryAsserts disabler;
         ro->invalidatePaintRectangle(mappedDirtyRect);
     }
     m_dirtyRect = FloatRect();
 }
 
 void HTMLCanvasElement::restoreCanvasMatrixClipStack(SkCanvas* canvas) const
 {
     if (m_context)
         m_context->restoreCanvasMatrixClipStack(canvas);
 }
 
 void HTMLCanvasElement::doDeferredPaintInvalidation()
 {
     ASSERT(!m_dirtyRect.isEmpty());
     if (is3D()) {
         didFinalizeFrame();
     } else {
         ASSERT(hasImageBuffer());
         FloatRect srcRect(0, 0, size().width(), size().height());
         m_dirtyRect.intersect(srcRect);
         LayoutBox* lb = layoutBox();
         if (lb) {
-            FloatRect mappedDirtyRect = mapRect(m_dirtyRect, srcRect, lb->contentBoxRect());
+            FloatRect mappedDirtyRect = mapRect(m_dirtyRect, srcRect, FloatRect(lb->contentBoxRect()));
             if (m_context->isAccelerated()) {
                 // Accelerated 2D canvases need the dirty rect to be expressed relative to the
                 // content box, as opposed to the layout box.
                 mappedDirtyRect.move(-lb->contentBoxOffset());
             }
             m_imageBuffer->finalizeFrame(mappedDirtyRect);
         } else {
             m_imageBuffer->finalizeFrame(m_dirtyRect);
         }
     }
@@ skipping 566 matching lines @@
 {
     return FloatSize(width(), height());
 }
 
 bool HTMLCanvasElement::isOpaque() const
 {
     return m_context && !m_context->hasAlpha();
 }
 
 } // blink